Paleobiogeographic study of the carboniferous and permian brachiopods from the Akiyoshi Terrane

笔者对秋吉地体石炭纪腕足类化石的研究取得了以下成果：1.石炭纪秋吉石灰岩腕足动物区系成分从Millerella yowarensis带到Pseudostaffella antiqua带有明显的变化。早石炭世代表性的属和种在M.yowarensis带之下几乎全部消失。在晚石炭世和早二叠世，一些残留物和新出现的不同的属是M.yowarensis带的特征。在Pseudostaffella antiqua带中，大部分元素被新出现的属所取代，其中一些属是早二叠世冷水省的代表性元素. Millerella yowarensis带和Pseudostaffella antiqua带分别含有亚洲特有属Weiningia和日本特有属Neocomphoria. Millerella yowarensis和Pseudostaffella antiqua带与纳穆里阶A（或S）相对应 ...更多信息 Erpukhovian）和Namurian C（或Midle Bashkirian）的西欧和俄罗斯。石炭纪秋吉石灰岩群的腕足动物都生长在生物礁环境中。纳木里期A和C的动物区系成分发生了明显的变化，并在这两个带中出现了地方属，这可能是由于全球气温下降的影响，特别是在高纬度地区。常盛组的腕足类是由秋吉海山崩塌后，秋吉灰岩群增生而来的，它不仅对确定常盛组的时代，而且对根据腕足动物群评价古生物地理状况都有重要的意义，这些腕足类正处于研究准备阶段。广岛上二叠统Karita组的腕足动物可能与常盛组相关，Yanagida等人对此进行了描述和讨论。少

Following results for my study on the Carboniferous brachiopods in the Akiyoshi Terrane have been obtained.1. The faunal elements of the Akiyoshi Limestone Carboniferous brachiopods show a remarkable change from the Millerella yowarensis Zone to the Pseudostaffella antiqua Zone. Early Carboniferous representative genera and species are almost all disappeared beneath the M.yowarensis Zone. Some remnants and the newly appeared genera which diversed in the Late Carboniferous and Early Permian characterize the M.yowarensis Zone.2. In the Pseudostaffella antiqua Zone most elements are replaced by the newly appeared genera of which some are the representative elements of a cool water province in early Permian time.3. The Millerella yowarensis and Pseudostaffella antiqua Zones contain some endemic genera such as Weiningia and Neoschizophoria which distribute in Asia and Japan, respectively.4. The Millerella yowarensis and Pseudostaffella antiqua Zones are correlated withy the Namurian A (or S … More erpukhovian) and Namurian C (or midle Bashkirian) of Western Europe and Russia, respectively.5. The Carboniferous brachiopods of the Akiyoshi limestone Group all flourished in an organic reefy environment. A conspicuous change of the faunal elements between Namurian A and Namurian C, and the appearance of the local genera in these zones may be affected by the beginnig of the global decline of temperature, especially in the higher latitudinal regions.Following results were obtained in the Permian brachiopods in the Akiyoshi Terrane.1. The Permian brachiopods of the Tsunemori Formation which was accreted by the Akiyoshi limestone Group by the collapse of the Akiyoshi sea mount have a very important information not only for determining the age of the Tsunemori Formation but also for appreciation of the palaeobiogeographic situation based on the brachiopod fauna.These Permian brachiopods are now under preparation for study. The Upper Permian brachiopods from the Karita Formation, Hiroshima which may be correlative with the Tsunemori Formation have been described and discussed by Yanagida and others. Less